JP5364258B2 - Combustion gas scavenging supercharged internal combustion engine having at least two intake means - Google Patents

Abstract

The engine has a burnt gas sweeping inlet unit (14) and a fuel injection inlet unit (16) provided with manifolds (18, 20) that is controlled by inlet valves (22, 24). A burnt gas exhaust unit has an exhaust valve (34) associated to an exhaust manifold (36) and fuel injection units. The fuel injection inlet unit has an injector (26) with noses (28, 30) supplying a fuel e.g. petrol, to the fuel injection inlet unit in an operating mode of the engine and to the burnt gas sweeping inlet unit and the fuel injection inlet unit in operation of the engine by the noses.

Description

  The present invention relates to a combustion gas scavenging supercharged internal combustion engine having at least two intake means.

  In particular, the invention relates to an indirect fuel injection type engine, in particular a spark ignition engine.

  In this type of engine, the power transmitted by the internal combustion engine depends on the amount of air fed into the combustion chamber. Therefore, by compressing air before sending it into the combustion chamber, the amount of air can be increased and the power requirements can be met. The supercharging of air can be obtained by any means such as a turbocharger or a mechanical drive type compressor such as a screw compressor.

  As is well known, the stage of scavenging the residual fuel gas present in the combustion chamber is a process of discharging the residual fuel gas during the intake phase of the engine and replacing it with supercharged air, thereby reducing the amount of air fed into the cylinder. It can be increased further.

  As described in detail in Patent Document 1, the scavenging stage consists of overlapping the exhaust valve and the intake valve of the cylinder at the end of the exhaust cycle of the engine and at the start of the intake cycle. The superposition is obtained by simultaneously opening the exhaust valve and the intake valve to a certain degree, that is, up to about 10 degrees in the rotation angle of the crankshaft.

  In the example of the supercharged engine for indirect fuel injection described in Patent Document 1, at least one combustion gas exhaust means includes at least an exhaust valve, an exhaust pipe, and a pipe each holding a fuel injection device and the valve. And two supercharging intake means.

  Combustion gas scavenging involves, on the one hand, superimposing the exhaust valve and the other supercharged intake valve while keeping one supercharged intake valve closed and, on the other hand, air in the open intake valve. This is due to the fact that the pressure of is higher than the pressure of the exhaust gas still present in the combustion chamber.

  Next, the supercharged air fed into the combustion chamber is supercharged air that does not contain hydrocarbons because the fuel injection device is not operating. This air that does not contain hydrocarbons scavenges the exhaust gas present in the combustion chamber and discharges it through the exhaust valve. Thus, the supercharged air without hydrocarbons occupies the volume released by the exhaust gas, thereby significantly increasing the amount of air introduced during the engine intake cycle. When approaching the end of the scavenging phase, the exhaust valve closes and the other supercharged air valve opens, the fuel injector combined with this valve is activated, and supercharged air containing hydrocarbons is sent into the combustion chamber As a supplement to the supercharged air that does not contain any hydrocarbons, it is fed into the fuel chamber through the other intake means.

When the engine is operating in a normal condition that does not include a scavenging phase, both intake valves are opened, both injectors are activated, and supercharged air containing hydrocarbons is simultaneously fed into the combustion chamber through both intake pipes .
French Patent Application Publication No. 2886342

  Although this type of engine works well, it has the major problem of requiring two fuel injectors per cylinder. In addition to the cost of these injectors, not only does the fuel supply amount double, but the number of injector connections per cylinder and the number of control means associated with the injector can also be doubled. It is absolutely necessary. This also increases the possibility of failure and malfunction.

  The object of the present invention is to solve such a problem by an engine having a simple and inexpensive intake means.

  The present invention relates to an indirect injection internal combustion engine that can operate according to a combustion gas scavenging mode or a normal mode, particularly a spark ignition supercharged engine, which includes at least one cylinder including a combustion chamber, and at least two intakes. One means is an intake means for scavenging combustion gas, the other means is an intake means for fuel injection, and each means has at least two intake means each having a pipe controlled by an intake valve; An internal combustion engine having at least one combustion gas exhaust means including an exhaust valve combined with an exhaust pipe and at least one fuel injection means, the fuel injection means has a fuel injection device including two nozzles; The two nozzles can supply fuel to the intake means for fuel injection through only one of the nozzles when the internal combustion engine operates in the combustion gas scavenging mode. When the internal combustion engine is operated in the normal mode, the one of the intake means through one of the two nozzles, the other inlet means through the other, respectively, characterized in that it is possible to supply fuel to a combustion engine.

  The fuel injection device advantageously has switch means for supplying fuel to the nozzle.

  The internal combustion engine preferably has a calculator for controlling the injection parameters of the fuel injection device.

  Other features and advantages of the present invention will become apparent upon reading the following description of non-limiting embodiments with reference to the drawings.

  According to the present invention, the above problem can be solved by an engine having a simple and inexpensive intake means.

  FIG. 1 particularly shows a direct fuel injection type (gasoline, LPG, CNG, etc.) supercharged internal combustion engine, in particular a fireworks ignition engine.

  This engine comprises at least one cylinder 10 with a piston (not shown) and a fuel mixture of supercharged air and fuel or supercharged air and fuel to which recirculated exhaust gas (EGR) is added. And a combustion chamber 12 in which the mixture burns.

  The cylinder 10 has at least two intake means 14 and 16, and during the combustion gas scavenging phase, one intake means 14 is used as a scavenging intake means, and the other intake means 16 is used as an injection intake means. The scavenging air intake means 14 can supply to the combustion chamber supercharged air that does not contain hydrocarbons for the scavenging phase or supercharged air that contains hydrocarbons for normal engine operating conditions. The injection and intake means 16 can supply supercharged air containing hydrocarbons to the combustion chamber whether the engine operates in a combustion gas scavenging state or in a normal state.

  Usually, such an intake means is provided in a cylinder head generally provided in such an engine, an orifice opened into the combustion chamber 12, a pipe 18 communicating with the orifice, and an intake valve suitable for closing the orifice. 22 and 24. The two tubes are preferably configured to be substantially parallel to each other while being connected to an air supply means such as an intake manifold (not shown).

  A fuel injector 26 having two nozzles 28, 30 (or two jets) is arranged in the tubes 18, 20 so that fuel can be fed into the tubes 18, 20 according to the engine operating mode. This injection device is supplied with fuel from a single fuel supply pipe 31, and the fuel is distributed between the nozzles by the switch means 32.

  The cylinder 10 also has at least one combustion gas exhaust means. In the present embodiment, it is two exhaust means each including an exhaust valve 34 and an exhaust pipe 36.

  The engine may also have a spark plug 38 that allows the combustion of the fuel mixture contained in the combustion chamber 12 to begin.

  The scavenging intake valve 22 and the injection intake valve 24, together with the exhaust valve 34, by means of means 40, 42 which allow the change of the valve lift pattern with respect to the opening and closing times and the lift times of these valves independently or collectively. Be controlled. These means are more commonly referred to as VVT (variable valve timing) or VVA (variable valve actuation).

  The control means 40, 42 are typically provided in any engine and are controlled by an engine calculator 44 having a mapping or chart that allows modification of the valve lift pattern depending on the operating conditions of the engine. The engine calculator 44 also controls injection parameters of the injection device 26 such as selective fuel supply to the nozzles, injection time, and the like.

  With reference to FIG. 2, the injector 26 has two nozzles 28, 30 each controlled by needles 46, 48 whose displacement is controlled by switch means 32. The switch means advantageously has an electromagnetic coil 50, 52 for each needle having plungers 54, 56 connected to needles 46, 48, respectively. The coils 50, 52 are connected to each other by a grounded conductor 58, and each coil has conductive wires 60, 62 connected to the engine calculator 44.

  Therefore, it is possible not only to control each nozzle independently of each other, but also to change the ejection parameters of one nozzle relative to the other nozzle.

  When the engine operates according to a supercharging mode that includes combustion gas scavenging, the engine calculator 44 initiates a combustion gas scavenging phase. Therefore, the engine calculator controls the control means 40 and 42 so that the valves are overlapped. At this stage, the piston is located near top dead center, the exhaust valve 34 is opened, the intake valve 24 of the injection intake means 16 is located in the closed position, and the intake valve 22 of the scavenging intake means 14 is located in the open position. The injection device 26 is inoperable. That is, the nozzles 28 and 30 are blocked by the needles 46 and 48.

  The gas is discharged from the exhaust valve 34 to the exhaust pipe 36 due to the pressure difference between the pressure of the supercharged air not containing hydrocarbons at the position of the valve 22 and the pressure of the residual combustion gas existing in the combustion chamber 12. Replaced with supercharged air not included.

  As soon as the scavenging phase of combustion gas is completed, the closing operation of the exhaust valve 34 is controlled by the control means 42, the scavenging intake valve 22 is kept open, and the opening operation of the injection intake valve 24 is controlled by the control means 40. . The engine calculator then controls coil 50 by wire 60 and moves plunger 54 by the electromagnetic field generated from the coil, thereby opening nozzle 28 while injecting fuel only into tube 20. The fuel mixture is thus fed into the combustion chamber 12.

  In a normal engine operating state having an intake mode that does not include scavenging of combustion gas, the intake valves 24 and 26 and the exhaust valve 34 are controlled as usual. Therefore, near the top dead center of the piston, the exhaust valve 34 is located at the closed position, and the scavenging intake valve 22 and the injection intake valve 24 are opened. The engine calculator is such that the two coils 50, 52 are powered by the wires 60, 62, the needles 46, 48 move to supply fuel to the nozzles 28, 30 and inject fuel into the tubes 18, 20, respectively. Activating the injector. This allows the fuel mixture to be fed into the combustion chamber through the respective tubes.

  In the present invention, fuel can be fed into the injection intake pipe or both intake pipes simply, reliably, and economically by a single injection device.

  The invention is not limited to the examples described above, but encompasses any variant or equivalent embodiment.

1 is a schematic view of an internal combustion engine according to the present invention. FIG. 2 is a detailed view of a member of the engine according to FIG. 1.

Explanation of symbols

10 cylinder 12 combustion chamber 14, 16 intake means 18, 20 pipe 22, 24 intake valve 26 fuel injection device 28, 30 nozzle 32 switch means 34 exhaust valve 36 exhaust pipe 40, 42 control means 44 calculator 46, 48 needle 50, 52 Coil 54, 56 Plunger 58 Conductor 60, 62 Wire

Claims (3)

An indirect injection internal combustion engine, in particular a spark ignition supercharged engine, which can operate according to a combustion gas scavenging mode or a normal mode, comprising at least one cylinder (10) including a combustion chamber (12), and at least 2 One intake means (14, 16), one means (14) is an intake means for scavenging combustion gas, the other means (16) is an intake means for fuel injection, and each means is an intake air. At least one combustion comprising at least two intake means (14, 16) having pipes (18, 20) controlled by valves (22, 24) and an exhaust valve (34) combined with an exhaust pipe (36) In an internal combustion engine having gas exhaust means and at least one fuel injection means,
The combustion gas scavenging mode occurs when the exhaust valve (34) and the intake valve (22, 24) are opened simultaneously ,
The fuel injection means has one fuel injection device (26) including two nozzles (28, 30), and the two nozzles are arranged in the one when the internal combustion engine operates in the combustion gas scavenging mode. Fuel can be supplied to the intake means (16) for fuel injection only through the nozzle (30), and when the internal combustion engine operates in the normal mode, one of the two nozzles (30) is used to An internal combustion engine characterized in that fuel can be supplied to the intake means (16) through the other (28) to the other intake means (14).   2. Internal combustion engine according to claim 1, wherein the fuel injection device (26) comprises switch means (32) for supplying fuel to the nozzle (28, 30).   The internal combustion engine according to claim 1 or 2, wherein the internal combustion engine has a calculator (44) for controlling an injection parameter of the fuel injection device (26).

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